While using gem like resin, the most efficient way to get rid of the air bubble is to vacuum degassing or pressure casting. However, these require expensive equipment. The alternative way is to use utility lighter (heat gun). By making the epoxy resin warmer and thinner, the air bubbles would be out easier. Please move the lighter back and forth from the surface of the bubbles to avoid fire occured.
Fine Chemical Epoxy Formulator in Lycal Gem Like Resin, Waterproofing, Adhesive and Coating solution. Other material are includes acrylic cementitious, encapsulation.
